Why would God interfere? Humankind has freewill to make our own choices, if we choose to blow ourselves up and melt all the ice on our Earth, why would God intervene? That would completely defeat the point of being able to make choices in the first place. Plus, I think God is wise enough to see the bigger picture - we're not going to destroy our planet, just ourselves, and we're all going to die anyway, and continue on our own separate journeys.